Here’s a curious one.
The max size of a thin-provisioned VMDK on a VMFS5 datastore is 2TB.
If you create a new VMDK you’re allowed to create it at 2048GB/2TB.
However when you go to expand an existing VMDK that is less than 2TB you can only grow it in 34.05GB chunks from the GUI.
From the command line you can expand it in one fell swoop (note that 2048g doesn’t work as you have a 2048GB-512b size limit – the GUI resizes for you)